1. Field of the Invention
The present invention pertains to the field of self contained underwater breathing systems and particularly relates to a manifold with a flexible hose that when connected to the cylinder valves of two cylinders (or tanks) containing compressed gas can funnel the gas therefrom to a single regulator.
2. Description of Related Art
Currently, divers double their bottom time by breathing off two cylinders containing pressurized air instead of one. One way of doing this is to simply attach separate regulators to each of the cylinder valves on the two cylinders thereby creating a redundant dual cylinder underwater breathing system. When the first cylinder empties, the diver would then open the cylinder valve on the second cylinder, retrieve the second regulator, abandon the first regulator, and breathe from the second regulator/cylinder instead of the first. The primary disadvantages with the redundant method are that it requires the diver to have two regulators, which are costly, and to juggle with two regulators throughout the dive as well as at the time the switch is made from one cylinder to the other. Another disadvantage of the redundant dual tank system is that it makes it impossible to rely on a diving computer. Unless the diving computer receives constant input from both tanks simultaneously, it cannot accurately provide a diver with vital information that may include, inter alia, the amount of dive time left or a decompression schedule. What the art needs is a more convenient method of making the air of both cylinders available to a single out source, therefore requiring only a single regulator, avoiding the juggle of switching from one cylinder and regulator to another, and enabling the use of a diving computer.
In answer to the need to channel air from two cylinders to a common outlet, one approach involves replacing the standard cylinder valves on the two cylinders with a special left and right cylinder valve which necessitates emptying the cylinders first. The specialized cylinder valves are essentially identical to standard cylinder valves except each also features a hollow, threaded extension/outlet to which a straight, rigid, metal cross pipe with contrastingly threaded ends is attached, thereby creating a rigid H-shaped manifold system that can bleed air from both cylinders, simultaneously (both valves open) or either cylinder (one valve open) as the diver chooses. The cylinders are filled with compressed air only after the specialized cylinder valves are installed on the cylinders. A regulator is attached to either one of the specialized valves.
One problem with the H-shaped manifold approach is it introduces moisture into the cylinders when refitting with the specialized valves. It is very important to keep the inside of a cylinder free of moisture to avoid corrosion forming inside the cylinder because corrosion within a damp pressurized cylinder occurs at a very rapid rate. Corrosion on the inside of a cylinder is very undesirable because it will enter and clog the breathing system. For this reason cylinders are very rarely ever completely emptied and are stored with some compressed air inside at all times. Emptying a cylinder to refit with specialized valves therefore not only requires removing the old cylinder valves and installing new ones, it also involves drying out the inside of the cylinder before filling with compressed air.
Another problem with the rigid H-shaped manifold is that the steel band type of harness must be used to hold the two cylinders in a fixed position relative to one another because any unsynchronized movement of the cylinders would exert stress upon the cross pipe and cylinder valve connections causing an air leak and/or damage to the cylinder valves or cross pipe. Utilizing a steel band type of harness to hold the two cylinders together is less desirable because they cost more, must be of the proper size for the cylinders being used, are heavier, and require tools and a significant amount of time to bind to the cylinders. Other types of cylinder harnesses, such as those employing bands with hook and loop type fasteners that weigh less, cost less, fit around nearly any sized cylinder, are quick to install and do not require tools, cannot be used to hold the cylinders together when a rigid H-shaped manifold described above is used. When a diver wishes to break down a dual cylinder system incorporating a H-shaped manifold to a single cylinder system, the steel band harness and cross pipe must be removed, and, depending on the particular circumstances, the cylinders emptied and the specialized cylinder valves replaced with standard cylinder valves, no small task.
The need for specialized cylinder valves and a steel harness make dual cylinder diving with an H-shaped manifold system very inconvenient. It means that a diver will probably have to use his own cylinders for all of his dual cylinder dives. Rarely, would any dive shop providing rental cylinders allow their rental cylinders to be emptied and temporarily refitted with another person's cylinder valves. Not only would it require emptying and drying rental cylinders twice, once to put the specialized cylinder valves on and once to remove them, and present all the risks associated with emptying a cylinder as discussed above, but such action would also take a great deal of labor as well subject the threads of the cylinder to potential damage. Where a diver uses his own cylinders and travels by aircraft to reach the diving destination, current rules require the cylinders be emptied and/or the cylinder valves removed while in air transport thus mandating drying and fitting specialized valves before the next dive, and, removing the valves for the return trip home only to dry out and refit the cylinders again.
In addition, regardless of whether the diver uses his own cylinders or rents them, once the breathable air supply of the two cylinders have been used up they must be refilled by a compressor which is usually available only at selected land based facilities. Thus, if a diver wants to make multiple dual cylinder dives on any one excursion using the H-shaped manifold system, that diver must take multiple sets of the H-shaped manifold/steel harness/filled cylinders or take along a compressor. The practical reality is that the H-shaped manifold makes it possible for a diver to make only one dual cylinder dive per diving excursion, and, that dive must be with his own cylinders.
What is needed in the art is a dual cylinder manifold that can be used with already filled cylinders having standard cylinder valves. Such cylinders are usually in abundant supply for rent from dive operators. By renting multiple pairs of already filled cylinders with standard cylinder valves such a manifold would enable divers to make multiple dual cylinder dives per excursion without having to transport their own cylinders, refit cylinder valves, possess multiple H-fold manifolds, or take along a compressor. What is further needed is a manifold that does not require the cylinders to be held in fixed relative positions thus requiring a steel band type harness.
One limited attempt to answer some of the problems just described that are associated with the rigid, H-shaped manifold is a manifold that employed a chrome plated, cast brass looped pipe that could be attached to standard cylinder valves. While this looped pipe manifold could be attached to already filled cylinders having standard valves, the looped pipe permitted only very minimal movement between the cylinders and therefore still required the steel band type of harness to be used to hold the two cylinders together. Further, the chrome plating of the looped pipe manifold had a tendency to crack with use thereby exposing the cast brass to corrosion, a very undesirable condition which could result in manifold leak and failure. However, neither the looped pipe manifold nor the H-shaped manifold answer the problem of providing a non-redundant dual tank diving system where the tanks are worn on the hips.
Other attempts to provide a diver with a twin cylinder dive are known, however, all present the many of the same problems as the H-shaped manifold. Jannson et al. U.S. Pat. No. 3,483,865 (1966), teaches a cylinder assembly where the air from a first cylinder is piped to a special valve on a second cylinder. Merrifield, U.S. Pat. No. 4,062,356 (1977), teaches a three cylinder system where one cylinder has a special reserve valve, the center cylinder has a special manifold, and the third cylinder a special valve and regulator. In Merrifield, compressed air from all three cylinders are channeled to the regulator valve and subsequently channeled to the second stage of a regulator. Mayes et al., U.S. Pat. No. 5,613,490 (1997), teaches a special regulator which channels air from two cylinders into a common outlet into which a standard cylinder valve is placed. All three of these references not only require that standard cylinder valves be replaced or augmented by specialized manifold or regulating attachments to the cylinders, they all also require rigid, bracket type harnesses to hold the cylinders into close parallel proximity.
What is still lacking in the art is a dual cylinder manifold that can be used with any size, already filled cylinders without using specialized valves and nearly any type of harness to hold the cylinders. It is to this end the present invention is addressed.
Accordingly, it is an objective of the present invention to provide an improved and novel dual cylinder manifold that can be connected to dual cylinders bound together by nearly any type of cylinder harness.
Another objective of the present invention is to provide a unique dual cylinder manifold that when connected to dual cylinders permits considerable movement and/or distance between the cylinders without damage to the manifold and/or cylinder valves.
A further object of the present invention is to provide a novel dual cylinder manifold that does not require the replacement of existing cylinder valves with specialized cylinder valves in order to connect said manifold to dual cylinders.
Yet another object of the present invention is to provide a unique dual cylinder manifold that can be connected to dual cylinders and a single regulator in standard supply.
Still another object of the present invention is to provide a dual cylinder manifold that can be connected to two cylinders of the same or differing sizes.
Yet another object of the present invention is to provide a kit of components from which to assembly and incorporate a manifold of the present invention to a dual cylinder and a regulator thereby forming a dual cylinder, self contained breathing system.
Another object of the present invention is to provide a manifold for use in a non-redundant dual cylinder diving system where the dual cylinders are spaced apart such as when worn on the hips during cave or wreck diving.
These and still further objects as shall hereinafter appear are fulfilled by the present invention in a remarkable manner as will be readily discerned from the following detailed description of the exemplary embodiments thereof.